Probably not photoshopped, more likely just different species and the one on the bottom has been butterflied and laid with the meat touching the ground so it looks much larger. Neither one has really started to change that much at the point these pictures were taken. Towards the end of the season, at least for west coast salmon, they’ll often get a lot leaner and their scales turn a super vivid red. As they lose their fat reserves, the meat also becomes much more delicate.